Polyphenolic compounds, also known as catechins, are present in green tea and have been suggested to provide protection against variety of illnesses including cancer (Mukhtar H., Ahmed N. Am. J. Clin. Nutr. 71: 1698S-1702S (2000)). Sadzuka et al. showed that oral administration of green tea enhanced the tumor-inhibitoy effects of doxorubicin in mice.
The anti-cancer activity of catechins may relate to their effects on several factors involved in proliferation of cancer cells and their metastasis. Catechins are known to cause cell cycle arrest in human carcinoma cells (Ahmad N., Feyes D. K., Nieminen A. L., Agarwal R., Mukhtar H. J. Natl. Cancer Inst. 89: 1881-1886 (1997)). Polyphenolic fraction from green tea is shown to protect against inflammation and cytokines induced by tumors.
Polyphenolic compounds present as 30% dry weight in green tea. They include flavanols, flavandiols, flavonoids, and phenolic acids. Flavanols are the most abundant among the polyphenols in green tea and are commonly known as catechins. There are four major catechins in green tea: 1) (−)-epicatechin, 2) (−)-epicatechin-3-gallate, 3) (−)-epigallocatechin, and 4) (−)-epigallocatechin-3-gallate (EGCG). Among the catechins, EGCG is the major polyphenolic constitutents present in green tea.
EGCG is a potent anti-oxidant compound (J. Cell. Biochem. 265: 236-257 (1996)) and may attribute to the anti-cancer activity of green tea. Catechin compounds were reported to exercise its anti-metastatic activity by preventing the angiogenesis process (Cao Y., Cao R. Nature 398: 381 (1999)). EGCG has also been shown to interfere with the activity of urokinase (u-plasminogen activator), one of the most frequently expressed enzymes in human cancers (Jankun J., Selman S. H., Swiercz R., Skrzypczak J. E. Nature: 387-567 (1997)).
However, it is established that the bioavailability of polyphenols in humans is extremely low (Chen L., Lee M. J., Yang C. S. Drug Metab. Dispos. 25: 1045-1050 (1997); Yang C. S., Chen L., Lee M. J., Balentine D. A., Kuo M. C., Schantz S. Cancer Epidemol. Biomark. Prev. 7: 351-35 (1998); Bell J. R., Donovan J. L., Wong R., Waterhouse H., German J. B., Walzem R. L., Kasim K. Am. J. Clin. Nutr. 71: 103-108 (2000); Sherry Chow H. H., Cai Y., Alberts D. S., Hakim I., Dorr R., Shahi F., Crowell J. A., Yang S. C., Hara H. Cancer Epidemol. Biomark. Prev. 10: 53-58 (2001)). The references cited are hereby incorporated by reference by its entireties. The low tissue concentration greatly reduces the therapeutic value of polyphenols including EGCG. There is a constant need in finding a better composition containing polyphenols that is effective in the treatment of neoplastic diseases. We surprisingly found a composition comprising catechins, ascorbic acid, proline, and lysine that can exert a potent anti-proliferative and anti-metastatic activity against neoplastic diseases.